Best available cop-



BEST AVAILABLE COP- (N0 Model.)

H. C-ARLEY & T. MCKENNA.

ELECTRIC ALARM FOR STEAM GAG-ES. No. 294.195. Patented Feb. 26,1884.

WITNESSES t 'QVIIEIEPTOR: 8m

ATTORNEYS.

, UNITED STATES- BEST AVAILABLE co? PATENT OFFI E.

HARVEY (ARLEY AND THOMAS MCKEXNA, OF LONG BRANCH, XIUVJIIRSEY;

' SAID (,ARLEY ASSIGNOR TO-SAIDJIOKENNA. 4

ELECTRIC ALARM FOR STEAM-GAESs SPECIFICATION forming part; of Letters Patent No. 294,195, dated February 26, 1884.

I Application tiled May 1t, 1883. (No model.)

To all whom, ifi 11mg Homer-11 p Be it known that we, 1l.\ uvm' CARLl-ZY and 'luoMAs MeKi-ixm, of Long ,lh-aneh, in the county oi Moumout h and State of New Jersey, have invented a new and improved Electric Alarm for meant-(laces, of which the followin is a't'ull, clear, and exact description. ur invention relates to the combination, with a steam-gage,of an electric alarm,whereby any increase or decrease ot'steaiii-pressure in the boiler beyond certain tixed limits may be signaled at a distant place oroilice.

ltcl'ercuce is to be had to the accompanying drawings, forming part; ot this specification, in

15 which similar lctt'ersot' reference indicatecorres 'ionding parts in all the figures.

v 1lig'ure l is a front elevation oi a pressure 4 steam-gage having our invention applied A represents a steam-gagqwhich may be oi" the ordinary or 0t any approved construction. I; representsan electric switch; an ordinary electric-alarm bell; and l) represents an ordinary galvanic battery, all of which are put in electric connection with each other and with the grace A by th' .vires a, b, c, u, and c, the wire 1; leadiugtot he biudin ppostf, attached to the metallic casing; of the gage at any desired point, the wire a, which is but a eoiuinuat ion ol'the wire a, leading" through theswitch ii to the bindiug-postj", attached to the glass l'ace 1 of the gage A, and the wire cicadhtg from i the binding-post d, also attached to the glass face g, to the binding-post 1/, of the switch l2. Thebinding-posh!" is held in place upon the glass face 1 by the screw I!, that passes through an oriiiee'iu the glass, and this screw 4 also holds in plaeeagai ust the inside ot'tlu.- glass face 4/ the cireuit-plat'ej. 'lhe binding-post d is held in place by the screw It, passing through or formed upon the eircuit-plate l.', which screw serves the double purpose of attaching both the bindiug-post and the circuit-plate to the 'glass face These eireuit-platesj and l. are respectively the high and low pressure circuitplatcs ol'the gage, and have, by preference, a

curved form, and are both struck from the 5 same center; but. the curved portion of the. platej is less than a half-circle, so thataspace may he left. bet ween its ends and the ends of the plate I.-, as shown clearly in Fig. 1, in which the pointer l of the gage may fluctuate without 5 closing, the circuit and causingthe alarm. Up

-on the pointer l is secured the tlat spring at,

the free end ot which travels when the pointer turns in the same circle formed by the circular plates j 1:,- and 'inmiediately back of them, so that when in line with either ot the said plates it will close the electric circuit aml cause the bell -to ring;

To previ -ut unnccessaryd'rict ion ot'the'spring at in passing from the neutral or no-alarm 6 limit bet ween the ends ofthe plates j I; upon the plates elosiu the circuit, the free end of the spring is provided with the small anti-friction roller i, as shown clearly lll Fig. 2.

ln usetheswitch llaml hell (1 \vill'lie located at the pla'eeor in t heotliee whc're itis desiredto have the signal given. The platesj I; will be adjusted, the former by being turned'onthe serew [I asa center, the latter by loosening the eo\er aml turning it axially on the case of 7 thee-ace. so that the uppmatljaeeut ends of the plates will coincide with thegraduatimnuarks on thedial nl'tluigage. imlicatingthe minimum aml maximum pr ssure of steam desired to have maintained in the boiler when ruhuing. Steam now being raised in the. boiler to the minimum pressure, t he pointer! maytluctuate between the upper cmls ot'th platesj k without. closing the circuit; but it the pressure-0f steam goes above the maximum or below the 8 minimum limit, tllt t'll'tfllll will be closed by the contact. ot'the spring m with one or other of t he circuit-plates, prm'hlcd the switch-arm b ot'the switch it is turned upon the button If ot' the switch, thus giving the alarm, and the alarm will be giveu as soon as the pointer passes the neutral limitin either direction, and will continue as-long as the pointer re-' mains outside the neutral limit. hit if thearm 1; is. moved to the position shown in full 5 e-i-lie maximum limit cl pressure.- i

To increase o'i-diminish the neni'ral .limit fo within whi clithe pointer I may ilnel nai e when stea n iis np wit houtrclosing .t-lncircuit, it-

E only'neeessiiryto loosen th liintlillg-pnsi- 1" YQQIBCXOW Zr Qud' turn the plate j accordingly; and to change the position of the altaelnnem. upon thedial fora limit of higher or lower I the right or left; .on the edge oi ihe ("isc at the gage, to properly situate the plates I: antlj,

. 22o to'coineidewith any desired gradualioirmarks -.,11ponthedial.-

i-In most instances the gage will be inelosed 1 m an outer case having a glass door, which maybe locked, so as to prevent access to the i5 gage, .ereept; by the proper POI'SOII having the :1 key. i

Y If; will be understood that the biuding-post 1 f, being attached to the glass face is thus :erl'y insulated; and it; will also be under- 'ign'a-L to give the alarm it the pressiire, -the cover A will, as above nien- .fioned, be loosened, and the glass 1 nrned in.

- T EsTAvAiLABLEoo'P l Siood lhat where a melalliecircuit is used, as 5 shown in thetlrawings. thegageA will hesuil ablyihs'u'lated from the strain-boiler, aml also 1hat,ins t'eatl of using a meiallic circuit, a i ground-connection might heemploved where. the distance, from the boiler m the alarm f considerable,

Constructed in this manner, the appliance 1 is very cheap, and ii; is practical and reliable as adangcr-alarm,and for signaling neglect of duty onihe part; of the fireman or person in immediale ('harge .ot' the boiler; and it:- may be easily applied 0 anystca-in or other gage emp'loying a pointer.

claim as new and. desire to secure by Letters vl atent 4 The combination, with the steam-gage A, having the netallic binding-posts 11 ff, the electric switch L,-havin g binding-post d, the electric-alarm bell C, and the galvanic battery i- D, of the circuit-plates j 7:, struck from the same center, the screws II: h, the pointer l, and the fiat spring in, as shown and described.

HARVEY OARLEY.

" I THOMAS )ICKENNA.

\Vitnesses: A.

H. A. Wns'r, C. Si nGwIcK,

i t I -1-la\'ing thus described our invention, we 

